Casters that are commonly used comprise a base and a yoke with downwardly extending legs, the yoke being rotatably mounted on the base. An axle extends between the legs and a wheel is rotatably mounted on the axle.
It is heretofore been suggested that brakes be provided for such casters. Thus, in U.S. Pat. No. 918,636, a pedal is rotatably mounted on the axle exteriorly of one leg. Radial projections on the leg and pedal are normally engaged and when it is desired to lock the wheel, depression of the pedal forces the projections out of engagement camming the leg against the wheel. In U.S. Pat. No. 1,137,329, the pedal is interposed between the leg and the wheel and a projection on the pedal engages the inner surface of the leg to press pedal against the brake. In U.S. Pat. No. 1,863,349, serrated plates are provided between the wheel and one leg and the pedal is mounted exteriorly of the leg and includes radial projections that are normally complementary to projections on the leg but are cammed out of such relationship when the pedal is rotated. U.S. Pat. No. 2,227,832 forms radial projections on one leg which engage radial grooves or cam ways on the axle which, in turn, is rotated by a pedal to actuate the brake. U.S. Pat. No. 3,467,981 provides for pins or plungers to be forced through the leg against the wheel by a pedal.
Each of the aforementioned constructions requires substantial modification of the caster and has the disadvantage that it cannot be readily adapted to conventional casters. Accordingly, among the objectives of the present invention are to provide a caster brake mechanism which can be readily adapted to conventional casters; which is simple in construction and relatively low in cost.
In accordance with the invention, a washer is nonrotatably mounted on the axle exteriorly of one of the legs, and a pedal is mounted on the axle exteriorly of the washer. The pedal has arcuate circumferentially spaced cam ways. Each cam way is tapered inwardly toward the center thereof and a plurality of circumferentially spaced projections on the washer normally engaging the deepest portions of the cam ways such that when the pedal is rotated in either direction from said normal position, the cam ways force the projections axially inwardly thereby forcing the one leg against said wheel to lock the wheel against rotation, and when the pedal is returned to its original position, the braking force is relieved.